Covers for cotton bales have heretofore been constructed utilizing a woven jute construction. Such covers possess disadvantages in that they are relatively expensive and tend to contaminate the cotton with the jute fibers. Efforts to supply cotton bale covers having improved characteristics are illustrated in U.S. Pat. Nos. 3,647,061 and 3,674,139. Such covers are of laminated construction, however, and tend to be expensive, presenting further problems in that they are not sufficiently air permeable when the cotton is compressed for baling and tend to cause mildew. Ring spun yarn is impractical for use in the present application because of the high level of defects in the yarn making warp knitting impractical. By the use of open end spinning, it is possible to use a lower grade of cotton for the coarser counts and yet produce yarn of acceptable quality for warp knitting. Such fabrics may be made to any desired width and possess a true selvage. It is thus possible to produce a yarn consisting essentially of cotton and suitable to be used on warp knitting equipment for constructing a bale cover.
Normally, coarse yarn counts are not run on warp knitting machines especially when such yarns are constructed of lower quality fiber. Having determined that it is possible to run such yarn on warp knitting machines, it is necessary to find a stitch construction to meet the requirements of a bale cover. Cotton bale covers must maintain their shape and be substantially ravel proof so that the compressed bale will not deteriorate excessively, or the fiber of the bale contaminated, when the cover is cut for cotton sampling. In this connection in most warp knit fabrics, all ends are form connected whereas in woven fabrics, the ends are friction connected. Such construction utilizing coarse yarn counts provide suitable cover or opacity to protect and retain the fiber mass of the bale in compression. The yarns tend to keep separated maintaining spacing with less tendency for the yarns to bunch together. Moreover, such construction permits a design for balanced tear and tensile strength in both directions without overuse of one to achieve the other.
U.S. Pat. No. 4,071,138 to Wright discloses a cotton bale cover of warp knit possessing a balance of stretch characteristics in both directions and suitable absorption properties, and which is substantially ravel-proof. However, Wright teaches a cover knitted from a higher grade of cotton which adds to the expense of baling.
Further, the prior art teaches covers having external restraints which fixes the cover in place. Product sampling of the bale contents therefore requires a hole to be cut into the cover for sample removal, followed by the repair of the cover. In addition, should a restraint band break, prior art covers and restraining means requires that the bag be rebaled and rebanded.
Therefore, there is much room for improvement and variation within the art.